Pass error messages from native messaging to web-app.

remoting/host/setup/me2me_native_messaging_host.h

Index: remoting/host/setup/me2me_native_messaging_host.h
diff --git a/remoting/host/setup/me2me_native_messaging_host.h b/remoting/host/setup/me2me_native_messaging_host.h
index 8686c15fe29d425a10f4684d4e7907c95dc445c4..a0b7c299f809ce49121328635781fcccf0145c15 100644
--- a/remoting/host/setup/me2me_native_messaging_host.h
+++ b/remoting/host/setup/me2me_native_messaging_host.h
@@ -23,6 +23,10 @@ namespace gaia {
 class GaiaOAuthClient;
 }  // namespace gaia
 
+namespace tracked_objects {
+class Location;
+} // namespace tracked_objects
+
 namespace remoting {
 
 const char kElevatingSwitchName[] = "elevate";
@@ -114,16 +118,16 @@ class Me2MeNativeMessagingHost
   void SendUsageStatsConsentResponse(
       scoped_ptr<base::DictionaryValue> response,
       const DaemonController::UsageStatsConsent& consent);
-  void SendAsyncResult(scoped_ptr<base::DictionaryValue> response,
-                       DaemonController::AsyncResult result);
+  void SendAsyncSuccess(scoped_ptr<base::DictionaryValue> response);
+  void SendAsyncFailure(scoped_ptr<base::DictionaryValue> response,
+                        const std::string& error_message,
+                        const tracked_objects::Location& location);
   void SendBooleanResult(scoped_ptr<base::DictionaryValue> response,
                          bool result);
   void SendCredentialsResponse(scoped_ptr<base::DictionaryValue> response,
                                const std::string& user_email,
                                const std::string& refresh_token);
 
-  void OnError();
-
   void Stop();
 
   // Returns true if the request was successfully delegated to the elevated